//  Copyright (c) 2007-2017 Hartmut Kaiser
//
//  SPDX-License-Identifier: BSL-1.0
//  Distributed under the Boost Software License, Version 1.0. (See accompanying
//  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)

#pragma once

#include <pika/preprocessor/expand.hpp>

/// Expands to the number of arguments passed in
///
/// \param ... The variadic number of arguments
///
/// Example Usage:
/// \code
/// PIKA_PP_NARGS(pika, pp, nargs)
/// PIKA_PP_NARGS(pika, pp)
/// PIKA_PP_NARGS(pika)
/// \endcode
///
/// Expands to:
/// \code
/// 3
/// 2
/// 1
/// \endcode
#define PIKA_PP_NARGS(...)                                                                         \
    PIKA_PP_EXPAND(PIKA_PP_ARGN_(__VA_ARGS__, 63, 62, 61, 60, 59, 58, 57, 56, 55, 54, 53, 52, 51,  \
        50, 49, 48, 47, 46, 45, 44, 43, 42, 41, 40, 39, 38, 37, 36, 35, 34, 33, 32, 31, 30, 29,    \
        28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, \
        4, 3, 2, 1, 0))                                                                            \
/**/
/// \cond NOINTERNAL
#define PIKA_PP_ARGN_(_1, _2, _3, _4, _5, _6, _7, _8, _9, _10, _11, _12, _13, _14, _15, _16, _17,  \
    _18, _19, _20, _21, _22, _23, _24, _25, _26, _27, _28, _29, _30, _31, _32, _33, _34, _35, _36, \
    _37, _38, _39, _40, _41, _42, _43, _44, _45, _46, _47, _48, _49, _50, _51, _52, _53, _54, _55, \
    _56, _57, _58, _59, _60, _61, _62, _63, N, ...)                                                \
    N /**/
/// \endcond
